content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * -----------------------
   * WithChangeListener.java
   * -----------------------
   * (C) Copyright 2013, by Michael Zinsmaier.
   *
   * Original Author:  Michael Zinsmaier;
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 17-Sep-2013 : Version 1 (MZ);
   *
   */
  
  package org.jfree.data.extension;
  
  import java.util.EventListener;
  
  import org.jfree.data.general.SelectionChangeEvent;
  
  /**
   * DatasetExtensions that support change listeners can implement this interface.
   *  
   * @author zinsmaie
   */
  public interface WithChangeListener<T extends EventListener> {
  
      /**
       * adds a change listener to the dataset extension<br>
       * <br>
       * The listener is triggered if if changes occur except 
       * the notify flag is set to false (@link #setNotify(boolean)).
       * In the latter case a change event should be triggered as soon as the 
       * notify flag is set to true again.
       *  
       * @param listener
       */
      public void addChangeListener(T listener);
  
      /**
       * removes a change listener from the dataset extension<br>
       *  
       * @param listener
       */
      public void removeChangeListener(T listener);
      
      /**
       * Sets a flag that controls whether or not listeners receive
       * {@link SelectionChangeEvent} notifications.
       *
       * @param notify If the flag is set to false the listeners are no longer 
       *     informed about changes.  If the flag is set to true and some changes
       *     occurred an event should be triggered. 
       */
      public void setNotify(boolean notify);
      
      /**
       * @return true if the notification flag is active 
       */
      public boolean isNotify();
      
  }
  